public final class IdentityComparison extends BinaryExpression
operand0, operand1, operatorEFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, EVENT_FEED_METHOD, INHERITED_CONTEXT, INSPECTION_CONTEXT, ITEM_FEED_METHOD, ITERATE_METHOD, locationId, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, NAVIGATION_CONTEXT, NODE_VALUE_CONTEXT, PROCESS_METHOD, PUSH_SELECTION, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, W3C_CONSUMING, W3C_FREE_RANGING, W3C_GROUP_CONSUMING, W3C_MOTIONLESS, WATCH_METHOD| Constructor and Description |
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IdentityComparison(Expression p1,
int op,
Expression p2)
Create an identity comparison identifying the two operands and the operator
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| Modifier and Type | Method and Description |
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Expression |
copy()
Copy an expression.
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boolean |
effectiveBooleanValue(XPathContext context)
Get the effective boolean value of the expression.
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BooleanValue |
evaluateItem(XPathContext context)
Evaluate the expression
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ExpressionCompiler |
getExpressionCompiler()
Return the compiler of the IdentityComparison expression
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ItemType |
getItemType(TypeHierarchy th)
Determine the data type of the expression
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int |
getStreamability(int syntacticContext,
boolean allowExtensions,
List<String> reasons)
Get the "sweep" of this expression as defined in the W3C streamability specifications.
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boolean |
isGenerateIdEmulation()
Test the flag that indicates different empty-sequence behavior when emulating
comparison of two generate-id's
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Expression |
optimize(ExpressionVisitor visitor,
ExpressionVisitor.ContextItemType contextItemType)
Perform optimisation of an expression and its subexpressions.
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void |
setGenerateIdEmulation(boolean flag)
Set flag to indicate different empty-sequence behavior when emulating
comparison of two generate-id's.
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Expression |
typeCheck(ExpressionVisitor visitor,
ExpressionVisitor.ContextItemType contextItemType)
Type-check the expression
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computeCardinality, computeSpecialProperties, displayOperator, equals, explain, explainExtraAttributes, getArguments, getOperands, getOperator, hashCode, isAssociative, isCommutative, isInverse, iterateSubExpressionInfo, iterateSubExpressions, promote, replaceSubExpression, setFlattened, simplify, toStringaddToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, evaluateAsString, evaluatePendingUpdates, explain, getCardinality, getColumnNumber, getColumnNumber, getConstructType, getContainer, getDependencies, getEvaluationMethod, getExecutable, getExpressionName, getHostLanguage, getImplementationMethod, getIntegerBounds, getIntrinsicDependencies, getLineNumber, getLineNumber, getLocationId, getLocationProvider, getObjectName, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getStreamingAdjunct, getSystemId, getSystemId, hasVariableBinding, implementsStaticTypeCheck, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, iterate, iterateEvents, markTailFunctionCalls, process, resetLocalStaticProperties, setContainer, setEvaluationMethod, setFiltered, setLocationId, staticTypeCheck, suppressValidation, toPattern, toStreamingPattern, typeErrorpublic IdentityComparison(Expression p1, int op, Expression p2)
p1 - the left-hand operandop - the operator, as a token returned by the Tokenizer (e.g. Token.LT)p2 - the right-hand operandpublic void setGenerateIdEmulation(boolean flag)
flag - true if this function is being used to compare generate-id() outputpublic boolean isGenerateIdEmulation()
public Expression typeCheck(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException
typeCheck in class BinaryExpressionvisitor - an expression visitorcontextItemType - the static type of "." at the point where this expression is invoked.
The parameter is set to null if it is known statically that the context item will be undefined.
If the type of the context item is not known statically, the argument is set to
Type.ITEM_TYPEXPathException - if an error is discovered during this phase
(typically a type error)public Expression optimize(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException
This method is called after all references to functions and variables have been resolved to the declaration of the function or variable, and after all type checking has been done.
optimize in class BinaryExpressionvisitor - an expression visitorcontextItemType - the static type of "." at the point where this expression is invoked.
The parameter is set to null if it is known statically that the context item will be undefined.
If the type of the context item is not known statically, the argument is set to
Type.ITEM_TYPEXPathException - if an error is discovered during this phase
(typically a type error)public Expression copy()
copy in class Expressionpublic int getStreamability(int syntacticContext,
boolean allowExtensions,
List<String> reasons)
getStreamability in class ExpressionsyntacticContext - one of the values Expression.NAVIGATION_CONTEXT,
Expression.NODE_VALUE_CONTEXT, Expression.INHERITED_CONTEXT, Expression.INSPECTION_CONTEXTallowExtensions - if false, the definition of "guaranteed streamability" in the
W3C specification is used. If true, Saxon extensions are permitted, which make somereasons - the caller may supply a list, in which case the implementation may add to this
list a message explaining why the construct is not streamable, suitable for inclusion in an
error message.Expression.W3C_MOTIONLESS, Expression.W3C_CONSUMING,
Expression.W3C_GROUP_CONSUMING, Expression.W3C_FREE_RANGINGpublic BooleanValue evaluateItem(XPathContext context) throws XPathException
evaluateItem in class Expressioncontext - The context in which the expression is to be evaluatedXPathException - if any dynamic error occurs evaluating the
expressionpublic boolean effectiveBooleanValue(XPathContext context) throws XPathException
ExpressioneffectiveBooleanValue in class Expressioncontext - The context in which the expression is to be evaluatedXPathException - if any dynamic error occurs evaluating the
expressionpublic ItemType getItemType(TypeHierarchy th)
getItemType in class Expressionth - the type hierarchy cachepublic ExpressionCompiler getExpressionCompiler()
getExpressionCompiler in class ExpressionCopyright (c) 2004-2013 Saxonica Limited. All rights reserved.